This invention relates to a surgical fastener cartridge possessing an improved body tissue cutting knife assembly. The cartridge is adapted for use with a known type of surgical cartridge actuator apparatus, actuation of which causes rows of fasteners to be applied to body tissue and an incision to be formed between the rows, the fasteners providing effective hemostasis for the incision.
Surgical fastener applicator apparatus in which surgical fasteners are simultaneously applied to body tissue are known. Typically, these devices include a fastener holder positioned on one side of the tissue to be fastened, an anvil parallel to the fastener holder positioned on the other side of the tissue, means for linearly translating the fastener holder and the anvil toward one another so that the tissue is clamped between them, and means for driving the fasteners from the fastener holder so that the ends of the fasteners pass through the tissue and form finished fasteners as they make contact with the anvil assembly, thereby producing an array of finished fasteners in the tissue.
In common use are apparatus in which the fastener holder and anvil are removably mounted in or on an actuator for supporting and actuating the cartridge. The cartridge can be disposed of after a single use or it can be reused for another surgical fastening procedure after cleaning, sterilizing and reloading with a fresh cartridge. Also in use are fully disposable surgical instruments in which the cartridge and actuator are preassembled ready for use and disposed of after only a single use.
Although instruments of the type described above are available for performing several different types of surgical fastening procedures, an illustrative type of instrument is the so-called thoracic-abdominal surgical fastener which is typically used for applying rows of fasteners laterally through hollow body organs such as the thorax, trachea, stomach, uterus or intestines.
U.S. Pat. No. No. 4,665,916, the contents of which are incorporated by reference herein, describes a surgical fastener apparatus of the foregoing type. The cartridge includes an alignment pin which achieves and maintains proper relative positioning of the fastener holder and anvil components thereof. When the fully assembled instrument is about to be actuated, it is positioned in such a way that the body tissue to be fastened is clamped in place between the staple-ejecting surface of the fastener holder and the clamping pressure exerted against both sides of the tissue is sufficient to provide effective hemostasis along two linear sites which, upon actuation, or "firing", of the instrument, receive substantially parallel rows of fasteners on either side of an incision formed by a tissue cutting knife, also incorporated in the holder, the deployment of which is mechanically synchronized to immediately follow the insertion of the fasteners.